Seeding clouds a new fix for Reef

A PLAN to seed clouds above the Great Barrier Reef to prevent coral bleaching could cost $50 million a year, but a scientist says this would be a “drop in the ocean” for reef managers.

University of Sydney researcher Dr Daniel Harrison has presented research at the Great Barrier Reef Restoration Symposium, suggesting cloud “brightening” technology could be deployed across the marine park to help shade and cool down seawater.

Cloud brightening involves increasing a cloud’s reflectivity to reflect a greater amount of radiation away from the earth, producing a cooling effect.

Under the proposal, salt crystals harvested from seawater would be sprayed over atrisk reef areas, via mobile or island-based stations into the atmosphere, to seed clouds.

“You’d only do it when there was a risk of bleaching, so during El Nino years, or whether it was a hotter year than normal,” Dr Harrison said.

Nozzles capable of spraying the microscopic-sized crystals are currently being developed as part of the study, alongside a feasibility plan for applying the research park.

Dr Harrison estimated the cost of operating the island or barge-based stations to spray the crystals to be between $50 million to $100 million a year.

“The technology is so simple, but you do need a lot of stations – and including monitoring and associated jobs – but I think it’s a drop in the ocean compared to the Reef’s worth to the Australian economy,” he said.

He believed there was minimal environmental risk of manipulating the climate, however this aspect would be explored as part of the feasibility study.

“We’re only using natural ingredients of seawater – nothing else – and it replicates natural processes,” he said.

Australian Institute of Marine Science reef restoration director David Mead said manipulating sea clouds was one option under consideration for leveraging natural Reef attributes to increase the natural wonder’s resilience.

“Scaling up restoration techniques to be effective across thousands of reefs and billions of corals presents serious challenges, but we believe these are not insurmountable,” he said. within the marine